I ran the following commands I found in a tutorial:
$sudo iptables -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT $ sudo iptables -L
target prot opt source destination ACCEPT all -- anywhere anywhere ctstate RELATED,ESTABLISHED
The man page just says that -L "lists the rules in the chain." I understand the first 5 columns—but what about the last? What do these mean?